Having it ported through the slide would be the simplest, installing a threaded barrel the next way to go. There's not a lot to be gained on the 9mm by comping unless you're pushing towards major power factor.

More an educational question... Aesthetically I think it looks awesome, silly I know, but it does matter to me.
Just kinda getting a response as i am new to the shooting world and want to gain some knowledge...

Make that a longer threaded barrel. The comp would have to be threaded to match the barrel and probably have to use a locknut to secure it, because it would have to be removed anytime you need to remove the barrel. T'would be ugly.

Frankly, it's a waste of money. Instead of a comp on a 9, do 20 pushups a day and about 20 concentration curls (with more than beverage cans).

Thank you for everyone's input. As I said I am new to the shooting world and wondered about the process of how a compensator would be fitted to the pistol. I thought it would look bad *** to have it but have learned both hath at a nine REALLY doesn't need it and to put it on a carry gun is foolish...
Wishing you all a very merry Xmas....